Connection for filament and lead wires



April 23,1935. FL WS, JR 1,998,958

CONIIEKJ'JION FOR FILAMENT LEAD WIRES Filed April "7, l 930 IM TUP.

Ja 'zxz FLAI/I/S, JR.

BY Wm 2 1 2-5 Ar TURN-E Y.

Patented Apr. 23, 1935 UNITED STATES PATENT OFFICE CONNECTION FOR FILAMENT AND LEAD WIRES New York Application April 7, 1930, Serial No. 442,173

1 Claim.

My invention relates to electric incandescent lamps and similar devices which comprise a bulb or other container of glass or similar material and have mounted therein a filament or other energy translation device connected by leads to the base terminals. Heretofore it has been the practice to clamp the ends of the filament to the flattened ends of the lead wires. The flattening of said leads requires not only an additional step in manufacture but it is not suitable when the leads are composed of refractory metals. Such metals are apt to split when flattened, and

this is particularly true of molybdenum which is very desirable for lead wires. One of the advantages of molybdenum leads is that they may be of comparatively small diameter, thus lending elasticity and flexibility which serve to reduce the eflEect of shock. The object of my invention is to provide a new form of connection which will allow the use of molybdenum lead wires and which is also of advantage where the leads are of any other metal.

According to my invention, the inner end of the lead wire is bent over on itself without flattening and in the case of a coiled filament, a portion of the clamp disposes itself between adiacent coils and a single thickness of the wire is clamped between the sections of the lead. Further features and advantages of my invention will appear from the description which follows and from the accompanying drawing.

In the drawing Fig. 1 is a perspective view of an electric incandescent lamp comprising my invention; Fig. 2 is a perspective view on an enlarged scale of the joint between the lead wire and filament; and Fig. 3 is an elevation thereof.

In Fig. 1 is shown an electric incandescent lamp comprising the bulb III, the base H and the usual stem l2. The filament l3 which is coiled and of tungsten is supported by the anchor wires 5 I 4, the opposite ends of which are embedded in the glass arbor l5. As shown in the drawing, the inner leads each comprise two sections. The sections lG-l 1 may be of a metal such as nickel, While the sections l8l9 may be of molybdenum. 10 It will be obvious, however, that other metals may be used.

In Fig. 2 is shown the joint between one of inner leads l9 and the filament [3. An end portion 20 of the said inner lead is bent over or clamped against the main portion thereof but without flattening. A portion 2| of one of the turns of the coiled tungsten filament l3, which is a single thickness thereof, is clamped between the said portions of the inner lead. The-bent over portion 20 is shown as being disposed between adjacent turns of the coiled filament.

What I claim as new and desire to secure by Letters Patent of the United States, is:

In an electric device comprising a sealed bulb, the combination of a. closely coiled metal filament in said bulb and an inner lead connected thereto, an end portion of said inner lead being bent over on the main portion thereof without flattening and a single thickness of said filament being clamped between said portions of said inner lead, the clamping portion of said inner lead being disposed between adjacent turns of said coiled filament.

JOHN LAws, JR. 

